Quieting A Ball Mill

[uncrichie]

Hi everyone. I read an article about using celotex or ceiling tile material to build a box surronding the mill to help quiet it down. That material is hard to deal with on its own without a supporting wooden shell. To avoid that I was thinking of using 1" or 2" thick solid foam insulation sold at the usual building supply stores. Its easier to deal with and can be glued to itself avoiding a wooden shell for support. My question is do you think foam would be as good a sound deadener as the other materials? Also would I have to be concerned with potential static issues with the proximity of the foam to spinning pvc jars? Many thanks. Kurt

[mikeee]

Styrofoam and Eurothane foams tend to hold a lot of static charge.

 

Causes of Static Electricity Brass, stainless steel Generation of static electricity on an object by Rubber rubbing is known as the triboelectric effect. The following is a list of substances in the triboelectic Acrylic series. The list is arranged in such an order that when Polystyrene foam any two substances in the list contact one another and then separate, the substance higher on the list assumes Polyurethane foam a positive charge. Acetate Glass Human hair Nylon Wool Fur Aluminum Polyester Paper Cotton Wood Steel Acetate fiber Saran Polyethylene Polypropylene PVC (vinyl) KEL F Teflon^® The size of an electrostatic charge on two different materials is proportional to the separation of the two materials. Electrostatic voltage levels generated by nonconductors can be extremely high. However, air will slowly dissipate the charge to a nearby conductor or ground. The more moisture in the air, the faster a charge will dissipate. Table 10-1 shows typical measured charges generated by personnel in a manufacturing facility. Note the decrease in generated voltage with the increase in Nickel, copper, silver humidity levels of the surrounding air.

Table 10-1.-Typical Measured Electrostatic Voltages VOLTAGE LEVELS @ RELATIVE HUMIDITY MEANS OF STATIC GENERATION LOW 10-20% HIGH 65-90% High Low

WALKING ACROSS CARPET 35,000 1,500

WALKING OVER VINYL FLOOR 12,000 250

WORKER AT BENCH 6,000 100

VINYL ENVELOPES FOR WORK 7,000 600

COMMON POLY BAG 20,000 1,200

CHAIR PADDED URETHANE FOAM 18,000 1,500

[Col]

If the noise is an issue, the mill isnt located far enough away A rubber mill jar is the easiest option.

[mikeee]

Buy a box of ear plugs and give them away to your neighbors.

[Col]

Another option is to run a shop compressor or jackhammer to cover the noise of the mill

[PyroCube]

I think you need something heavy to absorb the lower frequencies of your ballmill, the heavier the better.

Styrofoam will help a bit against the higher ones but it won`t be that good. If you have any thick plywood or chipboard

around, use this. I made one out of 1" chipboard and it helps a lot, you still hear the ball mill but it`s much better than nothing.

 

 

Greets

[ollie1016]

Throw two thick duvets over your ball mill box. It'll be alot quieter. Use a cotton cover though!

 

Just a little reminder:

It's highly recommended that you operate your ball mill in a large outdoor suitable area, or in a ball mill bunker. Explosions can happen.

 

 

[Arthur]

The RUBBER mill jar is the answer to your needs. Certainly two sizes are available. If the mill is loud the neighbours will get annoyed and start to ask awkward questions.

[Bobosan]

The 15lb Lortone drums are rubber lined and produce a muffled rumble vs. the piercing rattling of hard PVC pipe. Edited September 15, 2013 by Bobosan

[uncrichie]

Thanks everyone.

[Col]

The RUBBER mill jar is the answer to your needs. Certainly two sizes are available. If the mill is loud the neighbours will get annoyed and start to ask awkward questions.

 

I have a 4.37L rubber "jar" with 13.5kg of lead media, you cant hear anything beyond 15-20ft. At 80ft, binoculars are the only way to tell if its running. I have a few 6.6L versions too

 

[Bobosan]

Looks like an old go-kart racing slick? Excellent re-utilization! ....quiet also.

[Col]

I wasnt paying $72 for a rubber jar with half the capacity. The tyres are much sturdier and 100% airtight as long as you dont buy one with a puncture

[mikeee]

Col,

 

The center rod/shaft that holds the lids on, does the milling media come in contact with it?

What type of material is the rod/shaft made of?

 

mikeee

[Col]

There`s no shaft, there`s two rubber pipe bungs that expand outwards and seal tight against the bead, You can lift the entire tyre up by one and it wont let go, the total weight is around 35lb. Fitted into a rigid smooth bore pipe, the fail point is around 60lbs, considerably more with the rubber tyre bead. The tyre holds a positive air pressure when its sealed which keeps it nice and round and lets you know there`s a 100% airtight seal.

[mikeee]

Col,

 

If you get a chance can you snap a photo of the cover assemblies that seal the tires.

I would imagine these rubber jars reduce the noise level while running compared to a pvc jar.

[Col]

I used to run hdpe one gallon jars and the noise level was around 100db. Here`s the dry run i did in the shed with the mill on a wooden shelf. There was no bp in the tyre for the test and the motor is making most of the noise. A hdpe jar would be deafeningly loud but this one just rumbles along.

When its running outside, you can feel the vibration in your feet 2-3ft from the mill but its nice and quiet otherwise

 

http://www.youtube.com/watch?v=SAm5N_dveiQ

 

Here`s another vid, the loose pulley on the motor was responsible for the intermittant whirring noise, i`ve since tightened the grubscrew and now it doesnt whirr.

 

http://www.youtube.com/watch?v=1CHsHdFNteo

Edited September 15, 2013 by Col

[Bobosan]

so where to find bungs of that diameter?

[mikeee]

Bobosan,

 

A wholesale plumbing supply house will have the larger bung plugs like those.

Not sure if the big box stores carry anything larger than 4" or not.

[Arthur]

A rubber mill jar with ceramic media is near enough SILENT which is good for me!

[uncrichie]

so where to find bungs of that diameter?

 

Very interesting idea, heres where I was just looking at them http://www.zorotools.com/g/Mechanical%20Test%20Plug%20Water%20Line%20Stub%20Out/00042614/ however not alot of sizing adjustment available. Looks to be hit or miss unless other sizes are available from different sources. I know someone that races midget racers maybe I can aquire a few worn out tires!

[Zingy]

Welding Blankets, or Welding Curtains are a very handy safety item, that seem to be under utilized here, for sound, and fire suppression, plus as an added precaution, of at least a minimal blast shield, especially for a PVC Ball Mill Jar. They are also useful as a last ditch effort, for grass, or light brush fires, if by chance, you exhaust your water fire extinguisher(s), and five gallon backpack(s). Edited September 18, 2013 by Zingy

[hotzy30]

^^